Redox behavior was observed in alkali alkaline earth silicate PDP (Plasma Display Panel) glass melts doped with sulfate and sulfide by square wave voltammetry (SWV). According to voltammograms produced at a temperature range of 1100 to and frequency range of 5 to 1000 Hz, both melts showed the same behavior in which there is one reduction peak at low frequency but another peak at an increase of frequency. Based on the frequency dependence of the peak current, self diffusivity of was determined. Based on the temperature dependence of the peak potential, standard enthalpy () and standard entropy () for the reduction of to were calculated.

Optimized volume production of nanoscale phosphor powders synthesized by radio frequency (RF) plasma process was developed for the application to plasma display panels. The nano powders were synthesized by feeding the both solid and liquid type precursors, and nanoparticle phosphors were characterized in terms of particle size, shape, and photoluminescence (PL) intensities. Computer simulation was performed in advance to determine the process parameters, and nano phosphors were evaluated by comparing with current commercial micron-sized phosphor powders. Practical feeding of both solid and liquid type precursor was proved to be effective for volume production.The developed process showed a potential as a production method for red, blue and green phosphor although the PL intensity still needs further improvement.

The Physical property changes of calcined clay by carburization were investigated studied. The carburization mechanism is the penetration of carbon which occurred during incomplete fuel combustion into crevice of clay structure. The experiments for elasticity and freeze-thaw resistance were conducted, and the results can be summarized as follows: Dynamic modulus of elasticity and also freeze-thaw resistance of calcined clay by carburization treatment increased more than 92% after testing 300 cycle, which was more improved than 88% of calcined clay. Therefore, it can decrease the possibility of winter-sowing, which is one the weakness of calcined clay. It is on the basis of the fact that the porosity of calcined clay by carburization treatment is about 12%, which indicates smaller pore spaces comparing with the 14% of porosity of calcined clay and those values were calculated by apparent porosity show and also supported by SEM images. Infrared emissivity of calcined clay by carburization treatment and calcined clay were respectively 0.92 and 0.9l at . However, those values were 0.91 and 0.88 at , which means infrared emissivity of calcined clay by carburization treatment shows 3.6% higher than the calcined clay. Moreover, within the wavelength range from 3 to , while the calcined clay had low infrared emissivity, the calcined clay by carburization treatment had increased infrared emissivity. It is inferred that it was affected by carbon element that has high infrared absorptivity within this wavelength range.

This paper indicates the investigation about the development of ET (Environmental Technology) industrial geopolymeric materials from mixture silica mine waste, coal fly ash and alkali activator solution (sodium silicate) by the geopolymer technique at ambient temperature. The results showed that higher compressive strength of geopolymeric mortar increased with a reduce of L/S ratio and increased along with an increase of coal fly ash content. The compressive strengths of geopolymer mortar on low silica of C Silica Mine and K Silica Mine are 18.7 MPa, 20.4 MPa, respectively. Compressive strength of geopolymeric mortar depends on L/S ratio and coal fly ash content added.. Additionally, scanning electron microscope (SEM) techniques are used to characterize the microstructure of the geopolymeric mortars. SEM observation shows that it is possible to have amorphous aluminosilicate gel within mortar. XRD patterns indicate the fact that geopolymeric mortar is composed of amorphous aluminosilicate phase, calcite and quartz.

Willemite () are a wide range of applications such as a phosphor host and an important crystalline phase in glass ceramics, electrical insulators, glazes, and pigments. In this study, Willemite precursors were synthesized with zinc silicate gels from mixture of zinc nitrate solution and various sodium silicate solution by the geopolymer technique. To examine the crystallization behavior, precursors were have been monitored by the XRD. A pure willemite phase was obtained at . TEM investigations revealed that the sample with 50 nm particle size was obtained via heat-treated at for W-3.

Ceramics are widely used as plasma resistant materials in semiconductor industries. However, the plasma erosion resistance has not been properly evaluated in terms of microstructural changes during the exposure to plasma. In this study, microstructure developments of were investigated under the fluorine plasma conditions. In polycrystalline alumina, uniform erosion throughout the specimen as well as spatially distributed local erosion were observed. Local erosion was much more severe in lower purity alumina. In contrast to the polycrystalline alumina, only uniform erosion was observed in single crystalline sapphire. These specimens, however, had practically the same erosion depth, which results in the incorrectly similar plasma resistance. This implies that the plasma erosion resistance of ceramics should be evaluated in terms of the microstructural changes, as well as the conventionally accepted erosion depth.

Aerosol Deposition Method (ADM) is a novel technique to grow ceramic thick films with high density and nano-crystal structure at room temperature. For these unique advantages of ADM, it would be applied to the fabrication process of 3-D integration ceramic modules effectively. However, it is critical to control the properties of starting powders, because a film formation through ADM is achieved by impaction and consolidation of starting powders on the substrates. We fabricated alumina thick films by ADM for the application to integral substrates for RF modules. When the as-received alumina powders were used as a starting material without any treatments, it was observed that the dielectric properties of as-deposited alumina films, such as relative permittivity and loss tangent, showed high dependency on the frequency. In this study, some techniques of powder pre-treatments to improve the dielectric properties of alumina thick films will be shown and the effects of starting powders on the properties of AD films will be discussed.

The preparation of FeB by SHS in system was investigated in this study. In the preparation of FeB, the effects of the initial pressure of inert gas in reactor, the content of Mg and in mixture on the reactivity and reaction products was investigated. The minimum initial pressure of inert gas in reactor for SHS reaction in this system was 25 atm, and as the pressure increased, the concentration of unreacted Mg decreased and combustion temperature increased. At the initial inert gas pressure in reactor of 25 atm, the optimum composition for the preparation of pure FeB was +3.43Mg+ 1.7Fe+. The FeB synthesized in this condition had an irregular shape and the particle size of .

Ceramic Fiber separator is the promising material for thermal battery system because it reduces the production cost and offers the potential to a new application compared to a pellet type electrolyte. The molten salt electrolytes for thermal battery were prepared by the impregnation of the commercial glass filters such as GF-A, C and F (Whatman, USA) with two types of molten-lithium salts, LiCl-KCl and LiK-LiBr-LiF. The wetting properties were evaluated by wetting balance test and wetting angle measurement. The wetting behaviors were strongly affected by the composition of the molten salts and the pore structure of the glass separators. The optimum wetting conditions for maximum loading and effective retention of the molten electrolyte were also studied.

Porous self-bonded silicon carbide (SBSC) ceramics were fabricated at temperatures ranging from 1700 to using SiC, silicon (Si), and three different carbon (C) sources, including carbon black, phenol resin, and xylene. The effects of the Si:C ratio and carbon source on porosity and strength were investigated as a function of sintering temperature. Porous SBSC ceramics fabricated from phenol resin showed higher porosity than the others. In contrast, porous SBSC ceramics fabricated from carbon black showed better strength than the others. Regardless of the carbon source, the porosity increased with decreasing the Si:C ratio whereas the strength increased with increasing the Si:C ratio.